Insulator-clamp.



D. S. NICOL.

v INSULATOR CLAMP.

APPLICATION FILED JULY 23. 1911.

' 1,266,615. Patented May 21, 1918.

UNITED sTAT s PATENT oFrroE.

DAVID S. NICOL, OF MONTREAL, QUEBEC, CANADA, ASSIGNOR TO THE SHAWINIGAN WATER 8c POWER COMPANY, OF MONTREAL, QUEBEC, CANADA.

IN SULATOR-GLAMP.

Specification of-Letters Patent.

Patented May 21, 1918.

Application filed July 23; 1917. Serial No. 182,267.

To all whom it may concern:

Be it known that I, DAVID S. NIooL, asubject of the King of Great Britain, and resident of the city of Montreal, in the province of Quebec and Dominion of Canada, have invented certain new and useful Improvements in Insulator-Clamps, of which the following is a full, clear, and exact description.

This invention relates to improvements in insulator clamps, and the object of the invention is to provide a clamp securable to the large insulators of power transmission lines for supporting air break switches, lightning arresters and the like.

A further object is to provide a clamp of simple and durable construction, which will obtain a firm grip of the insulator without danger of breaking same.

The device consists briefly of a spider preferably of cast aluminum having arms shaped at their extremities to engage in a groove of the insulator, and externally grooved for the reception of a clamping bolt. The ends of the bolt are held in a clamping plate which also engages the insulator groove. The central part of the clamp is provided with a rib designed to engage the conductor slot in the head of the insulator.

In the drawings which illustrate the invention:-

Figure l is a plan view of the device.

Fig. 2 is a front elevation with the clamping plate and bolt removed, showing the device in position on an insulator.

Fig. 3 is a side elevation with ing plate and bolt removed.

Fig. 4: is a side elevation of the clamp.

Referring more particularly to the drawings, 11 designates an insulator having a circumferential groove 12 near the top thereof and a diametric conductor slot 13 in the top. The clamp comprises a central or body portion 14 of circular or other suitable shape having a rib 15 for engagement in the conductor slot, and provided with a pluralthe clampity of radiating arms 16, preferably three in num her, and arranged apart as shown. Each of these arms arches downwardly, and is provided at its free end with an enlarged plate 17,- which is curved vertically and horizontally on the inner surface in accordance with the curvature of the insulator groove 12-, and is provided on the outer sur face-with a groove 18 for the reception of a clamping bolt 19. The ends of the bolt 19 are secured between jaws 20 of aclamping plate 21 by means of nuts 22 engaging in sunken faced portions 23 on the jaws, in order to prevent accidental displacement of the nuts. The inner surface 2 1 of the clamping plate is curved in conformity with the groove 12, and therefore is of the same radius as the plates 17.

In applying the device to an insulator, the clamp 21 and bolt 19 are removed, and the body portion is slipped over the top of the insulator, so that the rib 15 engages the conductor groove, and the plates 17 slide in the circumferential groove 12. The clamping bolt 19 and plate 21 are then applied, and the nuts 22 tightened up. This action naturally draws the plates 17 and 21 toward the central axis of the insulator, the arms 16 being sufficiently flexible for this. It will be readily seen that there is considerable bearing surface between the clamp and insulator. so that the load is well distributed. The thin arched arms 16 have sufficient flexibility to protect the comparatively brittle insulator from sudden stresses applied through the clamp, and thus save the same from breakage. The same feature of flexibility also insures an approximately equal distribution of the grip between the plates 17 and 21, so that the insulator is not unduly stressed at certain points, in order to insure proper grip at other points. The apparatus which is to be carried by the clamp is connected thereto by bolts or screws passing through the central portion 14, holes being drilled as required.

Having thus described my invention, what I claim is l. A device of the character described, comprising a spider having a plurality of contractible arms, a plate at the extremity of each arm formed for engagement with an insulator, and externally grooved, a clamping bolt engaging said plate grooves, and a clamping plate connecting the ends of the bolt and engaging in the insulator groove.

2. A device of the character described, comprising a body having a diametric rib for engagement in the conductor slot of an insulator, arched arms radiating from said body, plates at the extremities of said arms engageable in the circumferential groove of an insulator, a clamping member engagethe external surfaces thereof, a bar curved 10 similarly to said plates having jaws at the ends thereof, a bolt lying in the grooves of said plates and at its ends between the jaws of said bar, and nuts securing said bolt.

In witness whereof, I have hereunto set 15 my hand.

DAVID S. NICOL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

